The model 1521 was the last of Electrolux USA's metal cylinder vacuum cleaners. The major changes in performance and/or accessories were marked with color and name changes.
Here's the entire list of 1521s by production years:
1984-87 Diamond Jubilee--sand w/jade trim (some with name decal); PN5 or PN6
1987-88 Marquise--taupe w/sand trim (no name decal); PN6A
1988-89 Grand Marquise--light sand w/navy trim (no name decal--smooth cover trim); PN6A
1989-90 Legacy--light sand w/navy trim (no name decal--textured cover trim); pn 1622
1990 Ultralux--light sand w/navy trim (w/name decal); pn 1622
1990-91 Ultralux LX--light sand w/navy trim (w/name decal; pn headlight); pn 1692
1992-93 Ultralux Classic--navy w/light sand trim (w/name decal; pn headlight); pn 1693
All had braided hoses with the chevron tracers in colors that matched the machines. Tool colors were either sand or light sand. At one point the short crevice nozzle was replaced with the conventional crevice tool. I think another change was making the floor brush standard and the combo floor/rug tool optional. The Rug Washer was an option with the DJ. The Sidekick was an option beginning with the Marquise.
The Ultralux Classic colors were alternated to match the new Epic 6000SR (plastic body and w/onboard tools), but I think it was the same as the Ultralux LX in performance and accessories.